i second this and approve.
PG has some powerful features that are not at all obvious to the uninitiated.
This little “easter egg” is a prime example.
i would still like to have 1-click access to toggle these rules on/off to see how they affect the display like we have or the 4 primary pseudo classes shown :active :hover :focus and :visited
to conserve screen real estate, they could change with the context of what you were working on or they could be configurable by the user with different “profiles” we could switch between as needed.